Bathtub



FIG. 1 is a perspective view of a bathtub showing my new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a side elevational view thereof; and

FIG. 4 is a cross sectional view taken on line 4--4 of FIG. 3. 

The ornamental design for a bathtub, as shown. 